When designing and building an installation, such as an aircraft, it is often necessary to arrange components within the installation such that their arrangement meets certain criteria. A systems installation is a result of a design activity that consists of positioning physical system components inside an installation, such as an aircraft. During the early stages of a design phase of specifying the installation, the systems installation is defined by geometrical 3D models that define approximately the shape, the size and the location of each system. When the design progresses, the 3D models become more accurate, eventually taking the shape of the detailed product 3D drawings that are used to manufacture the individual parts. These models look like ideal representations of the system. By “ideal representations”, it is meant that they do not take into account flexibility due to gravity, or other interactions that might affect their standard shape or size.
3D computer aided design tools are used to support the definition and verification of the systems installation. A software package that can be used to model system components prior to installation is CATIA, by Dassault Systèmes.
The arrangement of components in an installation is a difficult task because an installation is made of interdependent components that must fulfil a large number of constraints. An incremental installation process is not feasible, since a slight movement of one component may enable the satisfaction of one constraint and the violation of one or more other constraints.
The process of performing a common cause analysis, which includes particular risk analysis, common mode analysis and zonal safety analysis is known from SAE ARP 4761. Its use for the development and certification of complex systems is known from SAE ARP 4754.